1. Field of the Invention
This invention relates to wear spots and more particularly relates to migrating wear spots in solid-state drives.
2. Description of the Related Art
Storage systems are increasingly using solid-state memories to store data. A solid-state memory may be a semiconductor memory device such as Flash memory. The solid-state memories may be incorporated into a solid-state drive. The solid-state drive may include a plurality of solid-state memories.
Solid-state memories and solid-state drives often have very low access latencies. In addition, solid-state memories and solid-state drives may suffer fewer mechanical failures such as those that are common to hard disk drives.
Data may be written to a solid-state memory such as a Flash solid-state memory by first erasing a data block of the solid-state memory. The entire data block is then written with the modified data. Thus, changing one word in a data block requires that the entire data block be rewritten.
Unfortunately, solid-state memories typically may only be erased and rewritten a finite number of times. For example, a NAND gate flash memory may be designed to be reliably erased and rewritten 100,000 to 300,000 times.
When data is stored in a storage device such as a solid-state drive, certain files and portions of files may be repeatedly modified while other files and portions of files remain relatively static. High use files and portions of files may be referred to as wear spots. The development of wear spots in a solid-state drive may limit the life of the solid-state drive to the relatively short life of the wear spots.